1. Field of the Invention
The present invention relates to an original reading and conveying apparatus for reading an original conveyed through a predetermined conveying passage and for feeding the original in a predetermined direction.
2. Description of the Related Art
In a Japanese Unexamined Utility Model Publication JP-U 3004160, for example, there is disclosed a facsimile which is equipped with an original reading and conveying apparatus. The original reading and conveying apparatus, as disclosed in the Publication, has a construction shown in FIGS. 5 and 6. With reference to FIGS. 5 and 6, this known original reading and conveying apparatus has a transparent plate 4 arranged in a reading area 2 of an original conveying passage, and a pressure conveying roller 6 is arranged over the transparent plate 4. The pressure conveying roller 6 has a rotation axis 8 and a roller portion 10 mounted on the rotation axis 8. The roller portion 10 is usually made of rubber and is pushed onto the surface of the transparent plate 4. Both end portions of the rotation axis 8 are rotatably supported by bearings (not-shown). On one end portion of the rotation axis 8, for example, there is mounted a gear 12 which is connected to and driven by a drive motor 14 via a drive transmission mechanism (not-shown). Under the transparent plate 4, moreover, there is arranged a reading unit 16 for reading picture image information of an original being conveyed through the reading area 2.
In this original reading and conveying apparatus, an original to be read is conveyed in a direction indicated by arrow 18. The original thus conveyed is moved through a clearance between the transparent plate 4 and the pressure conveying roller 6. When the original is conveyed through the reading area 2, it is pushed toward the transparent plate 4 by the roller portion 10 of the pressure conveying roller 6. As a result, the reading unit 16 reads the original being pushed by the roller portion 10, through the transparent plate 4. On the other hand, the pressure conveying roller 6 is rotationally driven in a direction indicated by arrow 20 (shown in FIG. 6) by the action of the motor 14, so that the original on the transparent plate 4 is further fed to the downstream side by the rotation of the pressure conveying roller 6.
However, the original reading and conveying apparatus thus far described has the following problems to be solved. Firstly, for a sufficient conveying force, the roller portion 10 of the pressure conveying roller 6 is made of rubber, so that a relatively high frictional force accordingly acts between the transparent plate 4 and the pressure conveying roller 6. This makes it necessary to generate a high turning torque for rotationally driving the pressure conveying roller 6 and to employ a motor which outputs a high torque.
Secondly, the pressure conveying roller functions also as a conveying roller for feeding the original to the downstream side. As a result, the original is fed by the transparent plate 4 standing still and the pressure conveying roller 6 to be rotationally driven, so that the performance to discharge the original in the reading area is lowered.